The movie shows the horizontal velocity (left) and horizontal temperature fluctuations (right) for the 2D hydrodynamical simulation of a three solar mass star at the zero-age main sequence. Both quantities are scaled by their respective horizontal mean value to account for the different amplitudes in the inner (lower amplitudes) and outer (higher amplitudes) parts of the model. The magnified regions show the convective core. The simulation has been performed with the fully compressible, time-implicit Seven-League Hydro (SLH) code.